1. Re-assess shoes - orthotics changed/adjusted ==> see a podiatrist
2. Re-asses running - could you have changed technique recently? Running volume/terrain? think back to when pain started appearing, both when first and this time round.
3. Self massage - slow deep friction. also - icing is excellent morning/night/after exercise, depending on severity and how much time you've got on your hands. a great way to spare fingers/ save time- keep a golf ball or a glass coke bottle in the freezer - and roll your foot over for about 5-10 minutes.
3. Sports physios are good.
Good luck!!!